Fujitsu advances color e-paper technology

October 10, 2007 Fujitsu has displayed the latest incarnation of its electronic paper products at CEATEC in Japan. Having previously unveiled flexible color e-paper, this year the company has changed the form factor into an "e-reader" - a prototype content browser the size of an A5 sheet of paper that’s lightweight, extremely portable and features a high-contrast, easy to read 4,096 color display with very long (up to 50 hours) battery life due to its ability to hold an image once it is displayed without drawing on any power.

The key advantage of the e-paper format is its ability to mimic the convenience of the traditional paper medium while requiring little power and incorporating the storage advantages of digital hardware like portable computers. Sony has just released the upgraded second version of its “Reader” digital book - a compact, black and white viewing platform that holds up to 160 full novels around at any time. Fujistu’s e-reader shown at CEATEC, labeled the FLEPia “Ubiquitous Content Browser”, can store the equivalent of one year’s worth of newspapers (allowing for 10mb per day with images) when using a 4GB SD card, or around 5000 books.

The Flepia has been developed in both an A4 and A5 format - 8” or 12” displays – that weigh 320 or 480gram respectively and are just 12mm thick. The display is either 8 or 4096 colors with XGA 768 x 1024 resolution, touch panel and button operation, and can be updated via a wireless LAN network.

The Fujitsu product utilizes a SD memory card slot and a USB 2.0 connection and is powered by a lithium polymer battery that delivers up to 50 hours running time when displaying 3000 pages at rate of 1 page per minute (in 8-colors).

Speakers are also incorporated into the unit which takes 10 seconds to redraw and wont blur when pressed with a finger.

Designed to be as easy to read as normal paper, the display is three times brighter than reflective LCD screens and works by reflecting red, green, and blue wavelengths when exposed to light. When sunlight or fluorescent light enter the screen, the respective wavelengths of these three colors are reflected by separate layers which sit above a light absorbing layer, all sandwiched into the e-paper screen. The design also alleviates the need for light polarizing substrates or color filters.

The key to the incredibly meager power requirements is the ability of the liquid crystal display (which uses cholesteric liquid crystals) to hold a high-contrast, semi-permanent image once displayed without requiring any power whatsoever.

Fujitsu Frontech are offering the Flepia device for sale as proof of concept to companies in Japan considering taking-up this type of color electronic display.

In terms of applications, take a quick look around at the myriad of applications for traditional paper and you should have some idea of the potential - everything from consumer media formats to advertising to signage for which much larger flexible displays are being developed (in In Tokyo late last year Hitachi trialled color e-paper advertisements on commuter trains) and business applications will be within the scope of this technology as we (finally) move towards a paperless society.